*4.15. Statistical Analysis*

Three pieces of every film sample were tested to obtain the values presented in Tables 1–4. The final value of each property is the mean value of such measurements. All experimental data were processed with the SPSS vr. 20 statistical software and the mean values and standard deviation values which are tabulated above, resulted assumed a confidence interval of C.I. = 95%. Hypothesis tests ran assuming a statistical significance level of *p* = 0.05 to ensure that different mean values of a property for different samples are also statistically different. The non-positive normality tests implied the non-parametric Kruskal–Wallis method for such investigations and statistically unequal mean values of all properties were confirmed. The equality or inequality assurance was tested according to the empirical Equations (1) and (2) which were explained in detail in previous works [40]:

$$\text{EA(\%)} = \frac{\text{Sign} - \text{p}}{1 - \text{p}} \cdot 100 \tag{1}$$

$$\text{IA}(\%) = \frac{\text{p} - \text{Sig.}}{\text{p}} \cdot 100 \tag{2}$$

All the mechanical and barrier properties of all kinds of films exhibit statistical inequal mean values. The significance Sig. value range resulting from the SPSS software is presented in the following table:

It is obvious from Table 5 that the values of properties E, σuts, ε%, WVTR, and OTR are different for different kinds of films while the values of the antioxidant activity are different but, in some cases, close to each other. Finally, it is obvious from Tables 4 and 5 that mean values of antimicrobial activity, in some cases are statistically equal while in other cases are statistically unequal.

**Table 5.** Significance level, equality, and inequality, assurance of mean values for Young Modulus (E), σuts, % elongation at break (ε%), WVTR, OTR, % Antioxidant.


Significance level *p* < 0.05.

**Author Contributions:** Synthesis experiment design, A.E.G., C.P. and C.E.S.; characterization measurements and interpretation, A.E.G., D.M., A.A., C.G., E.K., A.K., L.A., A.L., S.G. and C.E.S.; paper writing, A.E.G., C.P. and C.E.S.; overall evaluation of this work, A.E.G. and C.E.S.; experimental data analysis and interpretation, A.E.G., C.E.S., C.G., S.G., E.K., A.K., L.A. and C.P.; XRD, FTIR, OTR, tensile measurements, UV-vis spectroscopy, antioxidant activity, WVTR experimental measurements, and kiwi fruits packaging test A.E.G., A.L., A.A., S.G. and C.E.S.; SEM images D.M. and A.A.; antibacterial activity tests, E.K., A.K., L.A. and C.P. All authors have read and agreed to the published version of the manuscript.

**Funding:** This research was funded by the funding program "MEDICUS", Project F.K. 81541, of the University of Patras, Greece.

**Data Availability Statement:** The datasets generated for this study are available on request to the corresponding author.

**Conflicts of Interest:** The authors declare no conflict of interest.
